Numerical Simulation Of Vertical Natural Gas Storage Tank Release And Dispersion

The fire and explosion accidents caused by the leakage of the gas tank happen frequently in recent years. Once such accident occurs, it will probably bring a lot of property damage and loss of life, what’s more, the surrounding environment will be destroyed as well. By performing numerical simulations of the gas tank leakage accident, we can grasp the diffusion path of the leakage of gas and the distribution law of gas cloud, which provides the necessary technical guidance to the prevention and control of the spread of gas leakage.In this paper, the leakage accident of storage tank and it’s area is simulated to generate a three-dimensional simulation. Comparing the influence of wind direction, wind speed, leak location, and the size of the spill mouth, as well as the influence of inner pressure of the tank and the space between tanks to the process of leakage.When the tank leaks with the wind, the leakage natural gas would rapidly spread along with the wind, so it would not be stacked in the spill mouth, and the internal concentration of gas cloud would stay low. When the leakage is against the wind, since the direction of the wind and the leakage of the gas are opposite, the wind flow hinders the leakage, making the gas stacked around the tanks and increasing the internal concentration of gas cloud. The faster the wind flow, the lower the inner concentration would be. Besides, the closer the leakage position to the ground, the gas would be diffused difficultly, and it would increase the density. With the magnify of the leak mouth, it will leak more gas, the volume of gas cloud will be larger. In the storage tank area, the influence of the tank pressure to the distribution of gas cloud with the concentration in the explosion limit range after the leakage is not remarkable. While the large distance can make the leakage gas cloud spread farther and the thickness more smaller.The results of the study prove that, on the premise of boundary conditions and basic assumptions, the leakage with the wind is far more dangerous than that against the wind. And the increase of wind speed can promote the fusion of air and gas leakage and reduce internal concentration of gas cloud, which is a certain relief of the danger of leakage accident. Low leakage locations as well as the ground friction would all reduce the spread space of gas cloud, which lead to high concentration. The diameter size of spill mouth can directly affect the risk of the accident, but changing the internal work pressure of the storage tank doesn’t work to reducing the risk of accident. To some extent, increasing the distance between storage tanks can reduces the danger of the accident.